Electron discharge device



Dec. 28 1926. v

F. L. HUNTER, JR

ELECTRON DI SGHARGE DEVICE Filed Oct. 29, 1924 Fig.5.

Frer/erfcK L.

11V VEN TOR HI/r1124 JR /0 Patented Dec. 28, 1926. I

UNITED ST TES PATENT OFFICE.

FREDERICK L. HUNTER, '13., OF TOWACO, NEW JERSEY, 'ASSIGNOR TO DE FOREST RADIO COMPANY, OF JERSEY CITY, NEW JERSEY, A CORBORATION OF DELAVJ'ARE' ELECTRON DISCHARGE DEVICE.

Application filed October 29, 1924. Serial No. 746,616.

This invention relates to electron discharge devices, and while intended pr1 marily for power-or transmission purposes,

the principlesinvolved are. applicable-"to.

detecting and amplifying devices as well.

The objects of the invention are to pro vide an electron discharge device wherein the upper ends ofthe grid, filament and plate are held against relative lateral displacement; to provide means for thus hold: ing said parts against lateral displacement which will allow for heatexpansion thereof;

to maintain the plate and supporting means spaced from' the wall of the enclosure or bulb; to obtain such spacing by resilient imeans; to interposea doublespring support for the filament; to provide a channelshaped bracket extending straight from the stem to the plate; to obtain rigidity without impairing operation of the device; to secure simplicity of construction; and to obtain otheradvantages and results as may be brought out'in the followingdescription. I Referring to the accompanyingdrawing,

in which like numerals of reference indicate similar parts throughout the several views;

Figure 1 is an elevation of an electron dis charge device embodying my invention; 7

Figure 2is a similar view looking toward the right side of the device as shown in Figure 1;

Figure 3v is a vertical central sectional view taken online 33 of Figure 2; and

Figure 4 is a In the specific embodiment of the invention illutrated in said drawing, thereference numeral 1 indicates the usual enclosure or tube of glass. or other] suitable material; scaled and evacuaterh and provided atv its lower end with abase 2, having contact prongs 3 as usual. WVithin the enclosure or i tube, at the lower part thereof, is the usual cylindrical stem 4 substantially concentric with the tube, said stem having its upper end flattened so as to seal in the lead wires which pass upwardly therethrough. j-

" Around stein/i is positioned a c0llar 5 from which support is to be obtained for a plate 6 positioned above the stem and extending longitudinallyl of the tube. plate preferabl is shaped so as to provide two parallel si e walls joined; at their vertical or longitudinal ends by semi-cylindrical perspective view of a certainend ,walls. Vertical or longitudinal vanes 7 there preferably being ,two such vanes on each side wall. Projecting downwardly from each vane is a bracket 8, the lower portion of which is secured to the collar-5 on the stem. It.i,s to be observed that I prefer to employ a bracket of channel for mation so it will overlieopposite sides of the vane, thereby forming substantially a continuation of the vane. The inner or longitudinal edges of the brackets are each preferably bent. laterally so as to form a longitudinal flange 9.at right angles to the channel portion of the bracket. These flanges not onl structure but a so provide a part which will fit flatwise aga'instthe supporting collar and enable the partsto be strongly united.

add to the rigidity of the Preferably the brackets are secured to the collar and to the plate vanes by welding, but

obviously other means may be employed if so desired. It is to be particularlyobserved that the structure above described enables the brackets to be perfectly straight longitudinally, and in view of the flanged channel formation the same are very rigid and revent relative displacement of the plate and reduce vibration thereof to a minimum.

Extending upwardly in the space between I the side and end walls of the plate are the grid supporting posts 10 Said posts 10 are preferably substantially parallel and carry transverse grid-wires 11 arranged within the plate. The upper ends of the grid supporting posts 10 project above the plate and are preferably off-set toward each other so as to provide parallel end portions 12, 12 not so far apart as the main portion of said posts and constituting guides as hereinafter explained. Spaced from the upper ends of said end or guide portions 12, 12 of the grid supporting posts and extending transversely in sald direction. While there are a number of ways in which this hanger 14 may be constructed, I preferably make each in two parts and after being positioned, said parts are welded together. As clearly shown in Figure 4, provide as one part of the hanger .a clamp 16, which can be drawn tightly around the insulatory member by pinching portions of the circumference together, as at 17,to draw the remaining part of the circumference into close association with the insulatory member. Thisclamp 16 is prefcrably stamped out of a strip of metal, the

portion stamped forming half of the circum-- ference and the marginal portions at the sides of the stamped portion forming the other'half of the circumference. The length of the portion stamped is sufficient so as to permit the resultant ring to be slipped over the end of the insulatory member, after whichthe portion of the circumference 17 is pinched together and then the ends of the strip 18 are bent down and caused to depend at either side of the pinched portion 17. The other part 19 of the hanger is preferably made from tubing of proper size to telescopically fit over the ends of the grid supporting posts. Above the ends of the posts this tubing is flattened and forms a strip, which is bent around the insulatory member and clamp overlying the clamp in circumferential engagement therewith. The flattened tubing and the clamp are then spot-welded together, making the complete hanger.

It may be here noted that I prefer to notch the insulatory member at one part of its circumference where the clamp 16 is to engage the same, thus providing means for preventing theclamp from slidinglongitudinally of the insulatory member and also having a tendency to prevent the insulatory member from rotating.

At opposite ends of the insulatory member I have shown bow springs 20, which bend outwardly in engagement with the side wall of the container 1 and then inwardly in engagement-with the plate to which they are attached as by welding, As one means for securing the bow'springs to the insulatory member; I have shown a wire 21 extending through said-insulatory member and through the ends of the bow springs, outside of which thewire is benttransversely. The ends of said wire may be further bent to extend inwardly and then downwardly with their ends secured in the vanes of the plate, either telescopically or with appropriate bends and resiliency to permit necessary movement between the parts for heat expansion and other purposes.

It may also be noted that between the two obviously resist.

hangers, I support spring suspension device 22 for receiving and holding the filament 23.

Obviously in the use of my improved electron discharge device, the springs 20 bearing against the sidewall of the contamer, prevent the insulatory member or a the plate from being jarred against the sidewall, both in a direction longitudinally of the insulatory member and, in a'direction transverse thereof, this latter being due to the fact that the sidewall is concave and lateral movement of the springs, would necessitate a distortion thereof, whichthey The structure furthermore provides a double spring suspension for the filament, in that the spring suspension device 22 directly supporting the:fila ment upon the insulatory member is supplemented by the use of springs 20 supporting said insulatory member; Both pairs of springs likewise take careof displacement due to heat expansion and other causes, and the telescopicmounting of the hangers upon the grid posts likewise accomodates such dis lacement. 7 e

- bviously detail changes and modifications may be made in the manufacture and use of my electron discharge device, and I do not wish 'to be understood as limiting myself to the exact structure shown, except Having described my invention, I claim- 1'. An electron discharge device having a plate and grid, an insulatory member, and means resiliently mounting said insulatory member with respect to said plate.

2. An electron discharge device having a plate and grid, an insulatory member, means resiliently mounting said insulatory'memher with respect to said plate, and hangers joining the insulatory members with the grid, said parts having a relative freedom of movement in one direction.

3. An electron discharge device having'a plate and grid, an insulatory member, means resiliently mounting said insulatory member, and hangerssccured to the insulatory Ill) member telescopically engaging the grid so as to join the grid to the insulatory member with a freedom of movement in one direct1on.

4. An electron discharge device having a plate and filament, an insulatory member for supporting the filament, a spring support between said plate and insulatory memher, and a spring support interposed between the insulatory member and filament. 5. An electron discharge device having a plate and filament, an insulatory mem er supporting said filament, an enclosure for said parts, and a spring supporting said insulatory member from the plate and hearing against the sidewall of the container- 

